Car-lighting system



P. KENNEDY.

CAR LIGHTING SYSTEM.

APPLICATION FILED DEC.1,I916.

l l l I H] Patented June 3, 1919.

4 SHEETS SHEET I E @I M R 0 T N E V N BY J +/M ATTORNEYS.

P. KENNEDY.

CAR LIGHTING SYSTEM.

APPLICATION FILED DEC. 1. 1516.

1,305,970. Patented June 3,1919.

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CAR LIGHTING SYSTEM.

APPLICAHON FILED DEC. 1. ms.

1,305,970. PateiltedJune 3,1919.

,zz INVENTOR PAfP/C X Z411 8093 ATTORNEYS P. KENNEDY.

CAR LIGHTING SYSTEM.

APPLICATION FlLED DEC. 1, 19m

1 ,305,970. PaTPnledJune 3,1919.

4 SHEETS-SHEET 4- {NVENTOR BBfY PL LX j anneay ATTORNEYS UNITED STATES PriTENT cl rion.

PATRICK KENNEDY, 0F BROOKLYN, NEW YORK, ASSIGNOR TO CONSOLIDATED RAILWAY ELECTRIC LIGHTING AND EQUIPMENT COMPANY, OF NEW YORK, N. Y., A CORPORA- TION 0F MAINE.

CAR-LIGHTING SYSTEM.

Specification of Letters Patent.

Patented June 3, 1919.

Application filed December 1, 1916. Serial No. 134,248.

To all whom it may concern Be it known that I, PATRICK KENNEDY, a citizen of the United States, and resident of the borough of Brooklyn, in the county of Kings and State of New York, have invented certain new .and useful Improvements in Car-Lighting Systems; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The particular object of the invention is to provide an axle driven lighting equipment for railway cars in which close regulation of the output of the generator and of the potential on the lamp circuit are attained in an automatic manner by simple and reliable mechanism. To this end there is combined with the usual axle driven generator, storage battery, and lamp circuit, tWo sole noid resistance regulators of novel construction, one comprising a solenoid affected by the generator current and actuating directly by pressure upon a contact plate to regulate the generator output, and the other, of sub stantially the same construction, affected by the potential of the lamp circuit and actuating directly by pressure upon a contact plate arranged to cut series resistance in and out of the lamp circuit. The solenoid resistance regulators acting directly by pressure upon the contact plate are characteristic of my invention, and when constructed substantially in accordance with the following description afford automatic resistance regulation which is extremely delicate in the sense that it will respond to very slight variations in the strength of current or potential, as-the case may be, and yet is quite simple and entirely reliable, and has the advantage that it will regulate with a fine degree of accuracy and without any sudden pulsations or oscillations which would be noticeable at the lamps.

Although I show and describe the resistance regulator with particular reference to car lighting systems, I do not in any way limit myself to this particular application as it may be successfully used for automatically regulating other kinds of electric systems.

T lie-operative movement of the plunger of a solenoid is inherently of limited extent, so that in many devices usually enmloyed either the extent of movement is insufficient for the required separation of the contact terminals of a resisance winding, or its operative force is insuflicient to overcome the friction between the contact surfaces when subjected to requisite pressure.

In accordance with my invention, the plunger of a solenoid acts directly upon a contact plate having a plurality of flexible fingers which, upon pressure, successively contact with the terminals of a resistance Winding so that the desired range of resistance variation, with fine gradations, is within the small range of movement practically available when a solenoid is employed: rcliable contact under these severe conditions of vibration and jar experienced on cars is continually maintained by providing a yielding contact surface underv pressure; the mechanical resistance to the movement of the solenoid plunger is reduced to a minimum by carefully centering and balancing the plunger and by simplifying the transmitting mechanism by rigidly connecting the plunger with the contact plate the actionof the whole device is steadied by a dash-pot so constructed that the friction between its piston and casing is reduced to a minimum and sticking is thereby prevented; and oscillation of the plunger about new points of equilibrium is practically eliminated by combining a properly designed solenoid with a spring having an increasing resisting stress as the plunger is attracted.

In the accompanying drawings illustrating the preferred embodiment of my invention, Figure 1 is a vertical. section of one form of my regulator having the solenoid at the center of a circularly arranged resistance box; Fig. 2 is an elevation. partly in section, showing a modified arrangement of the solenoid and circularly arranged contact terminals of a resistance box: Fig. 3 is a plan view of the contact plate carrying the flexible fingers adapted to cooperate with the contact terminals of Figs. 1 or 2: Fig. l is an elevation, partly in section, showing the arrangement of the resistance grids and the Contact plate of the modification shown in Fig. 1; Fig. 5 is a horizontal section on line 55 of Fig. 4; Fig. 6 is a vertical elevation, partlyin section, of a modification wherein the resistances are linearly arranged in two compartments with the solenoid between them; Fig. 7 is atop view of Fig. 6; Fig. 8

is a section, partly broken away, on the line 88 of Fig. 7; Fig. 9 isa wiring diagram of acar lighting system illustrating the application of my regulators for regulating the generator output and the lamp voltage.

The solenoid is of ordinary construction and has an outer iron shell 1 which incloses a winding 2 suitably insulated from the annular iron end plates 3-3 and from the brass tube 4, by the insulating core 5. The solenoid winding may consist of one or more coils electrically connected or insulated from each other and each one is preferably of a conducting metal having a low temperature coeflicient of resistance in order that the regulation will not materially change under varying temperature. The terminals of the windings are brought out through the shell- Although not essential, it is desirable that the resistance terminals should be compactly arranged. The resistance itself may consist of ordinary windings connected to contact terminals of various forms or arrangements, but I prefer the compact arrangement of grids herein disclosed as being more advantageous for use in the restricted and inaccessible places on cars. The resistance grids 9 may be made from resistance metal and may have slots of various lengths, for the purpose of securing electrical paths of various resistances while further variations in electrical resistance may be obtained by varying the thickness of the grid. By combining these two methods I provide a grid of any resistance and therefore a resistance box of graded or varied resistance as desired.

In order that the regulator may operate satisfactorily the electrical variations produced in the circuit to be regulated by changes of regulator resistance as caused by the actuating solenoid should have such value as will not affect the stability of the regulator or cause hunting. The above condition is best attained by so proportioning the successive steps or grids of the regulator resistance that the electrical variations produced in the circiut to be regulated shall or a combination of the two, depending upon the resistance and current-carrying capacity required. The electrical connections between the plates may be made by metal pieces or in any other well known manner. The contact terminals may be electrically connected to the grids by wires, but I prefer to solder or otherwise mechanically and electrically connect the contact terminals to the grids and to use for the contact terminals a nonoxidizing metal ofhigh conductivity in order to effect good electrical contact with the minimum pressure and friction between the contacting members. The terminals of the resistance box are brought out to the binding. posts 18 which also connect with the external-electrical circuit to be regulated. The sets of resistance may be connected together as indicated in Fig. 9 so that if the fingers of the contact plate are all raised out of contact with the contact terminals, the electrical circuit will not be interrupted. In this way the circuit through the resistance is maintained continuous at all times and the spark which would otherwise form is very much reduced or entirely eliminated.

The contact plate 13 is made of laminated copper plates or other good conducting material and has fastened to it or made integral with it a yielding contact surface comprising, if desired, a plurality of flexible fingers 14 electrically connected together by the contact plate. The fingers are bent at an angle to the contact plate and have a regularly decreasing length for the purpose of successively contactin with or separating from the contact termlnals of the resistance upon movement of the solenoid plunger, so

that the number of contact terminals of the resistance engaged by the contact fingers is largely altered, andhence the resistance between the circuit terminals is largely altered, by linearly moving the plunger through a small distance. Although thearrangement could be reversed or variously modified in obvious ways, I prefer the construction shown wherein the weight of the moving system together with the stress of the spring 16 is suflicientto press all the fingers into contact with the terminals, while the magneticpull on the plunger tends to successively raise the fingers out of contact. Upon decreasing the magnetic pull the pressure on the contact plate increases and the fingers in contact are gradually spread, thereby producing an efiicient wiping contact in such manner as to maintain good electrical contact with minimum friction.

The contact fingers are arranged similarly to the arrangement of the contact terminals. In Figs. 1 and 2 there are two sets of circularly arranged fingers, and the fingers of each set successively vary in length in such manner that the corresponding fingers of the two sets are diametrically opposite each "ger of the other set which is in contact with the grid nearest the outgoing terminal and .finally out of the other circuit terminal. The grids not traversed by the current are short circuited by the contact plate and fingers. The arrangement of resistance is such that as more of the contact fingers are raised out of contact by increased pull of the solenoid, more resistance is cut into the electrical circuit and vice versa.

. The contact plate is connected directly to As a'result of this construction, the pressure acting on the solenoid plunger is balanced on the two sides so that no side thrust exists and hence the friction of the plunger sliding in the solenoid core is reduced to a minimum.

The spring 16 is arranged to oppose thepull of the solenoid and may act with the weight of the moving system or against it as desired. In the drawingsthe spring 16 opposes the solenoid and acts with the weight of the moving element to increase the contact pressure, since it presses against the .piston in the dash-pot on one sideand against the bottom of the solenoid core on the other side. Hence the spring performs the double function of opposing the magnetic pull of the solenoid with an increasing resisting stress and also increases the contact pressure between the contact fingers and the contact terminal.

i The most effective form of solenoid for the purpose here intended, is that in which there is a fixed core, such as 8 cooperating 'With a movable plunger such as 7. It is characteristic of such a solenoid that as the plunger moves toward the core, the reluctance of the air gap islessened and effective magnetic power on the plunger progres- .s1vely.increases, so that if-the current'in the but even in that case an oscillation about the new point of equilibrium will occur. It is to prevent this oscillation that thedash-pot is em ,loyed. I t'i's evident at this point that the -pot incombination with variable current in the solenoid winding produces an operable arrangement for the purpose, but

in this case the dash-pot will have to be of greater efi'ect, whereas the movements of the plunger would be more sluggish and slower than is necessary. This condition will not be materially improved by adding a weight to the plunger, since the added etlect would be constant at all positions of the plunger. Therefore, it is sometimes desirable to supplement the constant resisting efiect due to the weight of the moving system by a spring suitably arranged so that its action against the plunger progressively increases as the plunger rises.

In addition to this action of the spring, there-is a similar action between the contact fingers of the contact plate and the contact terminals of the resistance, due to the fact that as the contact spring progressively raises out of engagement, the upward pres-. sure thereof is reduced. Then as the plunger and contact plate rise, the increasing magnetic power on the plunger, due to the decreasing reluctance of the air gap is opposed by an increasing resisting force of the spring and by a decreasing aiding force of the contacting members.

The current or potential to be regulated may be adjusted at will by adjusting the contraction of the spring 16. By tightening the spring, the resisting force acting against the plunger is increased so thata symmetrical balance is obtained at a lower position of the plunger, which corresponds to a less amount of resistance in the circuit regulator. However, I prefer to set the spring to correspond with the minimum current for Which the regulator is to be ordinarily used and to readjust the current to be regulated in accordance with the equipment by other means, such as the adjustable shunt 63 shown in Fig. 9.

V In Fig. 9, 4:8 a shunt generator having a grid resistance 49, in series with its field.

position connects the battery alone to the 11 lamps 52. The switch 53 is for the purpose of connecting. or disconnecting the lamps at will. The amount of resistance 49 included in the shunt field circuit of the generator depends upon the position of the contact plate 12 54, which is controlled by the current flowing in the series and shunt windings 55 and 56 of the solenoid. If the current from the generator increases, the current flowing in the series coil of the solenoid causes the 12 plunger 57 to rise, thereby inserting more resistance in the field circuit of the generator, and decreasing the vol'ta e until the current decreases to its norma value. When I the battery reaches a predetermined condisolenoid. The shunt and series windings are in the same direction so that the plunger 57 will be raised and sufficient resistance 49 will be inserted inthe generator field circuit to reduce the generator voltage to that point at which the switch 50 automatically opens and disconnects the generator from the systerm In this way the battery charge may be interrupted at any predetermined condition.

A second solenoid resistance regulator is provided to control the potential at the lamps in response to variations arising at the supply end of the system. as well as in response to, changes in the lamp, load( The shunt winding 58 of this solenoid is so adjusted that when the voltage at the lamps tends to rise above or fall below the normal value, which would result in the Variation of the lamp current, the plunger 59 is raised. or lowered and the contact arm 61 is pressed down on the contact terminals of the resistance until sufiicient resistance is added to or subtracted from the circuit between the supply mains and the lamps to restore the voltage to the normal value. In this way the lamp voltage is continuously maintained at the proper value to supply the predetermined current to as many lamps as may at any time be in circuit. It will, of course, be

. understood that it is necessary, in order to attain the best results, to use one of the improved solenoid resistance regulators for regulating the output of the generator, and another one for regulating the voltage at the lamps, but it is possible to partially get the benefit of my invention by using one of the improved resistance regulators at only one of these points, substituting some other form of regulator at the other point.

Various modifications orchanges in the details of construction of my invention may be made without departing from the principle thereof.

I claim:

1. An automatic resistance regulator for electric circuits comprising a resistance divided into a number of sections, compactly arranged terminals for the resistance sections, a solenoid responsive to electrical variations inthe circuit to be regulated a plunger actuated by the solenoid, a contact member carried entirely by said plunger and having flexible contact fingers of successively varying lengths adapted to engage successive terminals of the resistance sec- 1 tions in accordance with the position of said proportioned that the electrical variations in the circuit to be regulated produced by successive resistance changes shall be so related to the electrical variations in said solenoid that are required to produce successive resistance changes as to maintain the stability of the regulator; substantially as described.

2. An automatic resistance regulator for electric circuits comprising a resistance divided into a number of sections, compactly arranged terminals for the resistance sections, a solenoid responsive to electrical variations in the circuit to be regulated, a plunger actuated by said solenoid, a contact plate carried entirely by said plunger and having a plurality of sets of flexible contact fingers of successively varying lengths adapted to engage successive terminals of the resistance sections in accordance with the position of said plunger, said resistance sections being so proportioned that the electrical variations in the circuit to be regulated produced by successive resistance changes shall be so related to the electrical variations in said solenoid that are required to produce successive resistance changes as to maintain the stability of the regulator; substantially as described.

3. An automatic resistance regulator for electric circuits comprising a resistance divided into a number of sections, compactly arranged terminals for the resistance sections, a solenoid responsive to electrical variations in the circuit to be regulated, a plunger actuated by said solenoid, a substantially circular contact plate connected at its center to said plunger and having at its periphery flexible contact fingers of successively varying lengths adapted to engage successive terminals of the resistance sections in accord ance with the position of said plunger, said resistance sections being. so proportioned that the electric variations in the circuit'to be regulated produced by successive resistance changes shall be so related to the electrical variations in said solenoid that are required to produce successive resistance changes as to maintain the stability of the regulator; substantially as described.

4. An automatic resistance regulator for electric circuits comprising a resistance divided into a number of sections, compactly arranged terminals for the resistance sections,.a solenoid responsive to electrical variations in the circuit to be regulated, a plun- .120 ger actuated by said solenoid, a contact member carried entirely by said plunger and having a plurality of sets of flexible contact fin gers of unequal length with fingers of corresponding length symmetrically disposed .With respect to the plunger so that side thrust on the plunger is eliminated when the fingers are in ngagement with said terminals, said fingers being adapted to engage successive terminals of the resistance sections in accordancewith the position 'of said plunger and said resistance sections being so proportioned that the elwtric variations in the circuit tobe regulated produced by sucof the regulator; substantially as described.

5. In an automatic resistance regulator for electric circuits comprising a I'BSIStMlOB divided into a number-of sections compactly arranged terminals for the reslstance sec tions, a solenoid responsive to electrical variations in the circuit to be regulated, at plunger actuated by said solenoid, a contact Inemer carried entirely by said plunger and having flexible contact fingers of successively varying lengths adapted to engage succeswive terminals of the resistance'sections and a spring adapted to both resist the movement of the plunger and to increase'thecontact pressure between the fingers of said contact plate and the terminals of the resistance sections.

6. In a regulator for electric circuits, a

sectional reslstance, a plurality of contact pieces electrically connected to the resistance sections, a solenoid responsive to elec trical, variations inthe circuit to be regulated, a plunger actuatedby said solenoid,

a contact member carried entirely by said plunger and provided with flexible contact fingers, so arranged that the plane of the contact surfaces of the fingers is inclined to.

the contact. pieces whereby the number of v fingers engaging the contact pieces may be greatly increased or decreased by gradually varylng'the contact pressure.

7. In a regulator for electric circuits, a

sectional resistance, a'plurality of contact terminals electrically connected to the resistance sections, a solenoid responsive to.

electrical variations in the circuit to beregu l lated, a plunger actuated by said solenoid, a contact member carried entirely by said plunger and provided with alplurality of.

groups of flexible contactifingers, the plane of the contact surfaces of the fingers of each nals may be greatly increased or decreased by gradually varying the contact pressure. 8. Inca regulator for electric circuits, a resistance having circuit terminals and two rows" of electrically connected grids," each grid having an exposed contact surface, a solenoid responsive to electrical variations in the circuit to be regulated, a plunger actuated by said solenoid a contact member carried entirely by the plunger and having two rows of electrically connected flexible contact fingers of differing length and of a suflicient number so that a small linear movement of the plunger considerably alters the number of contact fingers of each row in engagement with the contact surfaces of the grids, and largely alters the electrical resistance between the circuit terminals.

' In testimony whereof I aflix m si%nature. PATRICK KEIIN DY. 

